unity bar and launcher disappeared

Hi to u all
I am still new in Ubuntu. I was making modifications with a program installed recently (I do not remember the name but it was supposed to help to customise the desktop and may otherthings, the name is something like gsysconfig!!!).
So I was trying to activate a cube on the desktop so I was told to to deactivate something of the desktop... Finally the unity bar, the launcher are more reachable. I have a screen quite like a usual XP windows. O do not even know how to lauch any of the programs installed (skype, officewriter..)
Many thanks if you can help. Fyi I read the FAQ but did not really found my answer